A holographic recording medium for recording data holographically has been already invented (e.g. see JP-A-2004-029476). This holographic recording medium is a photosensitive recording medium which is formed in such a manner that a holographic recording layer made of a photosensitive material is provided on a disc-shaped support. Since data are multiplexedly recorded as interference fringes of laser light on the holographic recording medium, the holographic recording medium can have a larger data recording volume than that of a DVD which was heretofore a popular recording medium. Exposure of the holographic recording layers to light or deposition of dust on the holographic recording layers exerts a bad influence on the performance of the holographic recording medium. For this reason, the holographic recording medium is dealt with in the condition that the holographic recording medium is received in a cartridge having a light-shielding function and a dust-proof function (e.g. see JP-A-2003-317422 (corresponding to US 2003/0198177 A1)).
In addition, as a cartridge for receiving a disc-shaped recording medium, there have been known a cartridge having a cartridge body with an opening exposing a disc-shaped recording medium to the outside, and a shutter for opening/closing the opening (e.g. see JP-A-7-210912), and a cartridge having a light-shield plate (shutter cover) further provided in the outside of a shutter (e.g. see JP-A-2001-216754 (corresponding to US 2001/0010680 A1)).
In the invention described in JP-A-2004-029476, the holographic recording medium is received in a cartridge similar to a cartridge of a DVD-RAM. This cartridge is formed out of a material small in transmittance of light rays in a wavelength range exerting influence on the holographic recording layers. Although JP-A-2004-029476 did not give any description on the detailed configuration of the cartridge, it may be conceived that the cartridge has the same configuration as that of the cartridge described in JP-A-2003-317422 (corresponding to US 2003/0198177 A1).
In the invention described in JP-A-2003-317422 (corresponding to US 2003/0198177 A1), the cartridge is made of a material capable of blocking a color sensitive to the holographic recording layer. Moreover, a sponge-like light-shield material is attached to a mating portion of a movable portion for exposing the holographic recording medium to the outside. In addition, in the description, the cartridge is provided with a cartridge body for receiving a recording medium therein rotatably, an opening provided in the cartridge body and for exposing part of the recording medium to the outside, and a shutter for opening/closing the opening.
The invention described in JP-A-7-210912 has been described on the cartridge chiefly aiming at storage of a photomagnetic disc. In the cartridge, an opening drive recess is provided in an extension portion extended from the shutter in a closing direction of the shutter, and a shutter opening member disposed in a recording/reproducing apparatus for inserting the cartridge therein engages with the opening drive recess so as to open/close the shutter.
The invention described in JP-A-2001-216754 (corresponding to US 2001/0010680 A1) has been described on the cartridge having the shutter, a slide member fixed to the shutter and the light-shield plate provided in the outside of the shutter so that the shutter is opened/closed through the slide member.